Auto Rickshaw—Pedestrian Head and Neck Impact Injury Mitigation—An Analysis of Impact Material Alternatives, Their Costs and Their Benefits

Rapid motorisation of developing nations has led to road traffic accidents being the leading cause of fatal injuries in low- and middle-income countries. Auto-rickshaws act as a popular low-cost alternative to four-wheel-vehicles in developing countries, however, they are relatively unsafe, particularly during pedestrian impacts, since their structures and materials provide poor impact energy absorption. Passive safety systems can improve pedestrian-vehicle impact safety by increasing energy absorbtion within the vehicle structures. An investigation was conducted of the commonly impacted auto-rickshaw windscreen frame and windscreen, to develop easily implementable, improved, impact absorbing structural alternatives. Aluminium and magnesium, were compared as an alternative to the high carbon steel windscreen frame and polycarbonate, for the glass windscreen. Finite-element analysis (LS-DYNA) was applied to assessing head and neck injury risks by impacting a 50% percentile adult male anthropomorphic-test-device, at the front, side and rear. Impacts were simulated at, and offset of, the vehicle centreline at velocities between 10 and 40 km/h and the corresponding Head Injury Criterion (HIC15) and Neck Injury criterion, (Nij and Nkm), investigated. Aluminium-6016-T4 and magnesium-AZ31B windscreen frame materials and the polycarbonate (PC) windscreen produced the lowest injury risk of all the materials investigated, particulary those head injuries associated with upper frame impacts. The PC windscreen produced higher HIC values for centreline impacts than glass, since it caused impact at the upper windscreen frame. Of the materials investigated, the aluminium (6016-T4) frame and PC windscreen produced the greatest safety at the lowest cost; establishing that material alternatives can assist in impact injury mitigation.